Without using code, I'm basically trying to achieve the "Desired outcome" in this picture:
I want the constraint on the "Hello!" label to shrink its length when the screen height is shorter.
As you can see in "Actual result", the Button in the bottom is off the screen. I want the image view to have fixed width and height.
I know I can create IBOutlets for constraints and doing it by code like this kind of posts suggest (autolayout - make height of view relative to half superview height), but I'm trying to avoid using code as much as possible.
Side question: If there's no way to do this in IB, what are the best ways to do this in code?
Thanks for the help!
Yes. The easiest way to have this kind of "split height" constraint is to put a "header" view between your image view and the top of the screen, and embed your "Hello" label inside this new header view. Then add a constraint to keep the "Hello" label vertically centered inside the header view.
To keep the header view the right size, add constraints to keep the top of the header view pinned to the top of the screen, and the bottom of the header view to the top of the image view.
Then you'll just add constraints to keep the button and image view pinned to the bottom of the screen. (Or, see comment from Sulthan, below.)
In Xcode 5.1 (in beta), there is UI to make more general constraints, including the ones you want, but you have to do it like this or in code in earlier versions.
Related
In order to implement scroll view I do:
Create Cocoa Application
Go to XIB
Drag scroll view to the view window and set its constraints to 0
Everything seems fine until now
Under Bordered Scroll View (in the Document Outline) I press on Clip View and then View and resize that to any large number (under size inspector)
I add a button (for the sake of it) to the view (under clip view) (in the Document Outline) and sets its constraints
After this I immediately get the "Ambigious Layout. Position is ambigious for "View".
What am I doing wrong? Is this the proper way to add scrollview? It also seems rather difficult to add items to the scrollable area as I dont see the entire scrollable area in the xib.
Please help a noob.
In general this is a correct way to add a scroll view. (You can also create a view or set of sibling views, select them, and choose Editor > Embed In > Scroll View.)
If a view has no constraints, then Xcode will add sufficient constraints at build time. These constraints are not necessarily the ones that cause the view to behave like you want as things change size, but they're good enough to maintain the current layout of the canvas when things have their current sizes.
However, once you add constraints, Xcode will start insisting that the constraints are mutually-compatible (no conflicts) and sufficient to be unambiguous.
So, that explains why you get that warning. You have added some constraints, but not enough to make the layout unambiguous. You need to add enough. Xcode should explain in more detail what's needed, although there will necessarily be multiple possibilities for how to resolve the ambiguity.
In your case, I'm guessing that the size of the view in the scroll view is ambiguous. For example, you may have added constraints to position the button relative to the top and leading edge, and the button likely has intrinsic size, but you haven't constrained the view's bottom or trailing edges to the button. So, the size of the view could be anything.
Of course, rather than constraining the view's bottom and trailing edge to the button, you could just add explicit height and width constraints to it. Or whatever.
You may also need to constrain the view to the clip view.
You can also use Editor > Resolve Auto Layout Issues > Add Missing Constraints and see what Xcode adds. You can then change things from there if what Xcode added is not what you want.
For my Mac OS X app, I selected the controls on xib to embed in scroll view ( Editor > Embed In > Scroll View ) and applying the following constraints to Custom View (inside Scroll View -> Clip View) did work.
Where hight is to accommodate controls.
Using Auto Layout constraints, I am trying to set up a subview with a vertical position that never changes, even when the in-call status bar (or some other non-standard status bar) is showing. I don't want to position the view relative to the Bottom Layout Guide because I want its y-coordinate to be the same for 3.5" and 4" devices.
Here's an illustration of what I want to have happen:
Initially, I set up the subview with a "Top Space to: Top Layout Guide" constraint for its y-position. With this configuration, the In-Call Status Bar pushed the subview 20px downward:
Next, I tried replacing that constraint with "Top Space to: Superview," where Superview was the root view of the controller. No change. Is there some other way to maintain a constant y-position for a view with Auto Layout constraints? I know I could resort to handling this manually by subscribing to UIApplicationDidChangeStatusBarFrameNotification, but I'd like to keep things simple if I can.
Your label is positioned to have a margin on top, between the start of the view and the start of the label. When the status bar grows, your view is shrunk. If you wish the label to remain in the same place, you can listen to UIApplicationWillChangeStatusBarFrameNotification notifications and adjust your view's size and origin to offset the additional space of the status bar. If you only want your label to shift up, you can also listen to the notification above, and adjust the top space constraint accordingly.
No you cannot.
The frame looses 20 px height in Portrait :( and the layoutguides don't care about it.
So either you do what Leo Natan said and use the notifications UIApplicationWillChangeStatusBarFrameNotification
Or either you will have to use the bottomConstraint as you dont want to do.
I'm making a document viewer in Objective-C, I want to have a bar at the top of the page with a bunch of buttons in it which open up menus, change pages, etc. At the moment I'm using a custom view which then just has all of the buttons inside it, but my problem is that it isn't a static vertical height, so when the window resizes it changes the size of the custom view rather than my PDFView. Is there a way I can stop it from resizing, or is there a better method I should be using to create a menu?
Thanks!
With auto layout, you can just give the view a fixed height -- from the editor menu, choose Pin, then Height. Make sure that it then only has one vertical constraint, either to the top, bottom, or centerY.
Are you using Auto-layout ? You may have to play with it.
Without seeing the code it's hard to debug the problem. Post the snippet where you're re-sizing the views if you're not using auto-layout.
We have a label followed by a UIViewCollection. The height of the label is dynamically set based on its content. Based on the height of the label, we want to start the UIViewCollection as soon as the label ends. We are tracking the label x, y, width and height and adding some padding to y in the code to calculate the start of UIViewCollection. However, UIViewCollection does not move at all. Is it because of the specified storyboard? We tried it in ViewDidLoad and ViewWillAppear.
Also, if we replace the UIViewCollection with a label such that there are 2 labels one below another, we are able to dynamically load the start of the 2nd label if the code is placed in ViewWillAppear.
Please can someone help with moving the UIViewCollection up or down based on the previous label height?
Thanks in advance.
It may be because You use autolayout. You can switch off autolayout or set translatesAutoresizingMaskIntoConstraints YES for UIViewCollection, and than set current location
If you're using auto layout this is easy to do, and you don't need to do anything in code to keep track of the label's height. The label should have a height constraint to the top of the view and a spacing constraint to the top of the collection view (the length of that constraint will give you whatever padding you want between them). The collection view then needs a constraint to the bottom of the view. This setup will cause the collection view to get shorter when the label gets taller. If instead, you want the height of the collection view to stay the same, but move down (assuming that it's short enough that there's room to move down), give the collection view a fixed height constraint, and remove its constraint to the bottom of the view.
I can't seem to make my segmented control, which is within a tableview smaller?
I'm not sure what fixed and the width, which is default to auto does?
I can't change the width from 320 either.
Heres a screen shot.
UIKit is going to resize a header view to be the full width of the table. Put the segment control in a view, and make that view the header view.
I find that when you put custom controls in a table view header or footer it is often best to place them on top of a separate UIView and make that UIView the actual header/footer.